In the construction of streets, highways, residential housing developments, commercial developments, schools, airports and similar other types of construction projects, the road system generally is first marked out and the streets of the development are cleared and graded. Thereafter, the storm water drainage system for the development is constructed, which typically includes underground drainage pipes, collection basins, culverts, and drop inlets that form the connection between the storm water drainage system and a finished street side curb-and-grate inlet. As construction of the development continues, government regulations and building codes generally require that the storm water drainage system be kept substantially free of silt and sediment that might enter through the curb-and-grate inlet. Keeping silt and sediment out of the collection basins can, however, be difficult given additional grading and construction on site that can dislodge or disturb silt and sediment, which accordingly, will tend to migrate or be pushed towards the sides of the street by wind, water and construction activity and consequently is washed into the open curb-and-grate inlet. If silt and sediment are washed into or otherwise collect within the collection basins and/or other parts of the drainage system, the collection basins can become clogged. In that event, it becomes necessary to send workers down into the collection boxes to clean out the dirt and/or debris manually in order to comply with clean water regulations. Such cleaning operations are difficult as the pipes are somewhat cramped, making it difficult to maneuver. There is also the danger of cave-ins or collapses of silt, sediment, dirt, etc., that has built up around the sides of the collection basins, creating a significant risk of injury or even death to the workers below, as well as the negative environmental impact and clean water regulation violations from the migrating sediment.
Although the simplest solution to this problem would seem to be to seal the curb-and-grate inlet completely, this solution is not feasible because storm and run-off water must be permitted to drain through the drainage system to permit the ground to dry and to prevent storm water from eroding the work site and carrying soil and debris to adjacent lots, buildings or nearby lakes and streams. The streets and roadways also must be kept clear to prevent a potential traffic hazard from standing water.
In the past, various filter systems for protecting the curb-and-grate inlets of a storm water drainage system have been utilized. Unfortunately, most of these systems have suffered from various disadvantages, including, in some cases, a requirement that the inlet grate be removed from the drain inlet to install the filter system.
Accordingly, a need exists for a filter system for covering and protecting curb-and-grate inlets of a storm water collection basin of a drainage system to prevent silt and sediment from migrating into the inlet while allowing for the free and substantially complete drainage of storm water runoff into the curb-and-grate inlet.